At present, various atmospheric-pressure or pressurizing fluid feeding devices respectively use different pumps outputting different pressures. Conventionally, the transmitted fluid spontaneously flows into the pump or is sucked into the pump, then pressurized and output to the material receiving system by the pump. However, such a feeding device has the following disadvantages. Firstly, as the transmitted material directly contacts the pump, the related parts of the pump requires special materials; however, the selected material is hard to simultaneously satisfy the functional requirement of the pump and the requirements for preventing the pump material from polluting the transmitted fluid, preventing the transmitted fluid from corroding the pump, and preventing the transmitted fluid from loss. Secondly, even though the problem of material selection is solved, different transmitted materials normally demand their dedicated pumps so as to avoid mutual pollution, spending time in washing the pumps, and processing the waste water generated in washing the pumps; thus is increased the investment to the apparatuses and the cost to operate and maintain the apparatuses. For example, while different materials are added to the reactor in industry or laboratories, it is hard to find a material simultaneously satisfying the requirements for the performance of the pump and the materials transmitted by the pump; normally, different materials are respectively transmitted by different pumps. In medicine, an injection pump is used to infuse fluid into the patient; limited by the volume of the injection pump, the injection pump may be replaced several times, which increases the cost of administration and the probability of pollution. In laboratories, an injection pump is sometimes used to provide a high-pressure liquid to a high-pressure liquid chromatograph in a stable flow rate; because of directly contacting the liquid, the pump requires special pump material and pump structure; besides, the pump is hard to be cleaned thoroughly before the injected liquid is to be changed. Therefore, the existing technology cannot satisfy requirement. Hence, the present invention provides a fluid feeding device to solve the problems of the existing technology.